Process for breaking petroleum emulsions



Patented Jan. 27, 1953 PROCESS FOR. BREAKING PETROLEURI' EMULSION S Melvin De Groote, UniversityCity, Mo., assi'gnor to Petrolite Corporation,

a corporation ofDela- NoDrawing. ApplicationDecember l, 1-950, Serial No. 198,756

Claims.

This invention relates topetroleum emulsions of the water-in-oil type that are commonly rearev of significant. value in removing impurities.

particularly inorganic salts from pipeline oil.

Demulsification as contemplated in the present application. includes the preventive step of commingling the demulsifier with the aqueous component. which would or might subsequently be come either phase of the emulsion, in absence. of such precautionary measure. Similarly, such demulsifier may be mixed with the hydrocarboncomponent.

The demulsifying agent employed in the present process is a fractional ester obtained from a polycarboxy acid and a diol derived in turn by the, oxypropylation ofv a hexide. have the empirical formula CsHmOi with two oxygen-containing rings and two esterifiable hydroxyl groups. Their-structure can be illustrated by the probable structural formula of one of the Practically, the hexides are derived from hexitols,

by an anhydr-idizing reaction, in consequence of which the hexides are named by reference to the hexitols from which they can be formed, by changing the sufiix itol to ide. Thus mannitol yields mannide, sorbitol yields sorbide, dulcitol yields dulcide, etc. Each of the hexitols iscapable of forming a number of isomeric hexides. In this: application the terms mannide, sorbide, etc., are employed in the generic sense to cover all isomeric hexides formed from the respective hexitols. See U. S. Patent No; 2,387,842 to $01152- berg; dated" October 30,v 1945.

Thehexides are appropriately the dihydroxyl- The hexidesated" ultimate anhydrides obtained from hexitols which may. go through an intermediate stage involving the formation of compounds having 4 hydroxyls suchas sorbitammannitan and dulcitan. Re-st'atin'g what" has been saidpreviously in more elaborate manner, attention is directed to U. S. ,PatentNo. 2,322,821 to. Brown, dated June, 29; 1943. The following text is a substantially. verbatim excerpt.

The formation: of theethers from the polyhydric alcoholsinvolves dehydration. which may be accomplished by. heating and driving oil? water. The splitting off of water from 2 hydroxyls attached to polyhydric. alcohols can proceed both internally and externally. In internal etherification where the two hydroxyls are both attached to the same molecule of polyhydric; alcohol, formationlof the ether link: leads to oxide or carbonoxygen rings. Where the. disposition of the hydroxyl, groups-allows; the formation of rings hav ing four to seven. numbers, as is the. case with the hexitols, then internal etherification to produce cyclic internal ethers is, in general, the preferred reaction.

This internal ether formation can proceed in two stages with the formation of one or two carbon-oxygen ringsgiving rise tomonoor dianhyd'ro products. Inthe case-of'hexitols these may becalled generall'y-hex-itans and hexides; for example, sorbitan, mannitan, and dulcitan, and sorbide, mannide, and dulcide. Examples of such possible; ring structures aregiven herewith:

GTE CH HOCHCH0H H HO H CHOH \H H I c C +Hz0 H: OH: I OH on CH2 CH1 Hexitans, or monoanhydrides Hexides, or dianhydrides CuHsO(OH)4 CeHaOz(OH)2 In addition to internal etherification, external etherification can take place. Since this is a bimolecular reaction involving 2 molecules instead of the one molecule concerned in internal etherification, this external etherification tends to proceed to a lesser extent and becomes of importance principally when the internal condensation becomes difificult or impossible.

Specific reference is made to the two aforementioned patents as to appropriate procedures for producing sorbide, mannide, or dulcide, all of which may be considered as examples of suitable hexides.

If for convenience the hexide is indicated thus:

the product obtained by oxypropylation may be indicated thus:

with the proviso that n and 11. represent whole numbers which added together equal a sum varying from 15 to 80, and the acidic ester obtained by reaction of the polycarboxy acid may be indicated thus:

I H00away: ocinmon'owammfl omooomn' in which the characters have their previous significance, and 'n is a whole number not over 2 and R is the radical of the polycarboxy radical coon R\ and preferably free from any radicals having more than 8 uninterrupted carbon atoms in a single group, and with the further proviso that the parent diol prior to esterification be waterinsoluble and kerosene-soluble.

Attention is directed to the co-pending application of C. M. Blair, Jr., Serial No. 70,811, filed January 13, 19%9 (now Patent 2,562,878 granted August '7, 1951), in which there is described, among other things, a process for breaking petroleum emulsions of the Water-in-oil type characterized by subjecting the emulsion to the action of an esterification product of a dicarboxylic acid and a polyalkylene glyco1 in which the ratio of equivalents of polybasic acid to equivalents of polyalkylene glycol is in the range of 0.5 to 2.0, in which the alkylene group has from 2 to 3 carbon atoms, and in which the molecular weight of the product is between 1,500 and 4,000.

Similarly, there have been used esters of dicarboxy acids and polypropylene glycols in which 2 moles of the dicarboxy acid ester have been reacted with one mole of a polypropylene glycol having a molecular weight, for example, of 2,000 so as to form an acidic fractional ester. Subsequent examination of what is said herein in comparison with the previous example as well as the hereto appended claims will show the line of delineation between such somewhat comparable compounds. 01 greater significance, however, is what is said subsequently in regard to the structure of the parent diol as compared to polypropylene glycols whose molecular weights may vary from 1,000 to 2,000.

For convenience, what is said hereinafter will be divided into five parts:

Part 1 is concerned with the preparation of the oxypropylation derivatives of the dihydroxylated hexide;

Part 2 is concerned with the preparation of the esters from the oxypropylated derivative;

Part 3 is concerned with a consideration of the structure of the diols which is of significance in light of what is said subsequently,

Part 4 is concerned with the use of the products herein described as demulsifiers for breaking water-in-oil emulsions; and

Part 5 is concerned with certain derivatives which can be obtained from the oxypropylated diols. In some instances, such derivatives are obtained by modest oxyethylation preceding the oxypropylation step, or oxypropylation followed by oxyethylation. This results in diols having somewhat different properties which can then be reacted with the same polycarboxy acids or anhydrides described in Part 3 to give effective demulsifying agents. For this reason a description of the apparatus makes casual mention of oxyethylation. For the same reason there is brief mention of the use of glycid.

PART 1 For a number of well known reasons equipment, whether laboratory size, semi-pilot plant size, pilot plant size, or large scale size, is not as a rule designed for a particular alkylene oxide. Invariably and inevitably, however, or particularly in the case of laboratory equipment and pilot plant size the design is such as to use any of the customarily available alkylene oxides, i. e., ethylene oxide, propylene oxide, butylene oxide, glycide, epichlorohydrin, styrene oxide, etc. In the subsequent description of the equipment it becomes obvious that it is adapted for oxyethylation as well as oxypropylation.

Oxypropylations are conducted under a wide variety of conditions, not only in regard to presence or absence of catalyst, and the kind of catalyst, but also in regard to the time of reaction, temperature of reaction, speed of reaction, pressure during reaction, etc. For instance, oxyalkylations can be conducted at temperatures up to approximately 200 C. with pressures in about the same range up to about 200 pounds per square inch. They can be conducted also at temperatures approximating the boiling point of water or slightly above, as for example to C. Under such circumstances the pressure will be less than 30 pounds per square inch unless some special procedure is employed as is sometimes the case, to wit, keeping an atmosphere of inert gas such as nitrogen in the vessel during the reaction. Such low-temperature-low reaction rate oxypropylations have been described very completely in U. S. Patent No. 2,448,6634 to H. R. Fife, et al., dated September '7, 1948. Low temperature, low pressure oxypropylations are particularly desirable where the compound being subjected to oxypropylation contains one, two or three points of reaction only, such as monohydric alcohols, glycols and triols.

Since low pressure-low temperature-low reaction speed oxypropylations require considerable time, for instance, 1 to 7 days of 24 hours each to complete the reaction they'rare conducted a rule whether on a laboratory scale, pilot plant scale, -or large scale,- so as' to operate automati "cally. The prior'figure of seven days applies especially to large-scale operations. I have used conventional equipment with two added automatic features; '(a) a -solenoid' controlled valve which shuts on the propylene oxide in event that the temperature gets outside a predetermined and set range, for instance, 95 to 120 0., and (b) another solenoid valve'which shuts off'the propylene oxide (or for that matter ethylene oxide if it is being used) if the pressure gets beyond a predetermined range, such as 25 to "35 pounds. Otherwise, .the equipment is substantially the same as is commonlyemployed for this purpose where'the pressure 'of reaction is higher, speed of reaction is higher, and time of reaction is much shorter. In such instances such automatic controls are'not necessarily used.

'Thus, in preparing the various low temperature oxypropylation examples I have found it particularly advantageous to use laboratory equipment or pilot plant which is designed to permit continuous oxyalkylation whether it be oxypropylation or oxyethylation. With certain obvious changes the equipment "can be used also to permit oxyalkylation involving the use of glycide where no pressure is involved except the vapor pressure of r-a solvent, if any, which may have beenusedasa diluent.

vAs previously pointed out the method of using propylene oxide is the same as ethylene oxide. This point is emphasized only for the reason that therapparatus isso designed and constructed :as to use either oxide.

The "oxypropylation procedure employed in the preparation :of the 'oxyalkylated derivatives has been uniformly the same, particularly in light of the fact that a continuous automatically-controlled procedure Was employed. -In this procedure the autoclave was a conventional autoclave made of stainless steel and having a capacity of approximately '15 gallons anda working pressure of one thousand pounds gauge pressure. This ,pressureobviously is far beyond any requirement as far as propylene oxide goes unless there is a reaction of explosive violence involved due to accident. The autoclave was equipped with the conventional devices and openings, such as the I variable-speed stirrer operating at speeds from 50 R. P. M. to 500 R. P. M.; thermometer well and thermocouple for mechanical thermometer; emptying outlet; pressure gauge, manual vent line; charge hole for initial reactants; at least one connection for introducing the-alkylene oxide, such as propylene oxide or ethylene oxide, to the bottom of the autoclave; along with suitable devices for both cooling and heating the autoclave, such as acool-ing jacket, and, preferably, coils in addition thereto, with the jacket so arranged that it is suitable for heating with steam or cooling with water and further equipped with electrical heating devices. Such autocl-aves are, of course, in essence small-scale replicas of the usual conventional autoclave used in oxyalkylation procedures. In some instances in exploratory preparations an autoclave having a smaller capacity, for instance, approximately 3 liters in one case and about 1 gallons in another case, was used.

Continuous operation, or substantially continuous operation was achieved by the useof a separate container to hold the .alkylene oxide being employed, particularly propylene oxide. In conjunction with the smaller autoclaves, the contamer "consists essentially of a laboratory bomb having a capacity of about one-half gallon, or somewhat in excess thereof. In some instances a larger bomb was used, to wit, one having a capacity of about one gallon. This bomb was equipped, also, "with an inlet for-charging, and an 'edu'ctor tube going to the bottom of thecontainer so as to permit discharging of alkylene oxidein the liquid phase to the autoclave. A bomb having a capacity of about 60 pounds was used in connection with the 1'5-gallon autoclave. Other conventional equipment consists, of course, of the rupture disc, pressure gauge, sight feed "glass, thermometer connection for nitrogen for pressuring bomb, etc. The bomb was placed on "a scale during use. The connections between the bomb and the autoclave were flexible stainless steel hose or tubing so that continuous weighings could be made without breaking or making "any connections. This applies also to the nitrogen line, which was used to pressure the bomb reservoir. To the extent that it was required, any other usual conventional procedure or addition which provided greater safety was used, of course, such as safety glass protective screens, etc.

Attention is directed again to what has been said previously in regard to automatic controls which shut off the propylene oxide in event temperature of reaction passes out of the predetermined range or if pressure in the autoclave passes out of predetermined range.

With this particular arrangement practically all oxypropylations become uniform in that the reaction temperature was held within a few degrees of any selected point, for'instance, if C. was selected as the operating temperature the maximum point would be at the most C. or 112" C., and the lower point would be 95 or possibly 98 0. Similarly, the pressure was held at approximately 30 pounds within a 5-pound variation one way or the other, but might drop to practically zero, especially where no solvent such as xylene is employed. The speed of reaction was comparatively slow under such conditions as compared with oxyalkylations at 200 C. Numerous reactions were conducted in which the time varied from one day (24 hours) up to three days (72 hours), for completion of the final member of a series. In some instances the reaction may take place in considerably less time, i. e., 24 hours or less, as far as a partial oxypropylation is concerned. The minimum time recorded was about a 3-hour period in a single step. Reactions indicated as being complete in 7 hours may have beencomplete in a lesser period of time in light of the automatic equipment employed. In the addition of propylene oxide, in the autoclave equipment as far as possible the valves were set so all the propylene oxide if fed continuously would be added at a rate so that the predetermined amount would react within the first 15 hours of the 24-hour period or two-thirds of any shorter period. This meant that if the reaction was interrupted automatically for a period of time for pressure to drop or temperature to drop the predetermined amount of oxide would still be added in'most instances well within the predetermined time period. Sometimes Where the addition was a comparatively small amount in a 7-hour period there would be an unquestionable speeding up of the reaction, by simply repeating the example and using 4, 5 or 6 hours instead of 7 hours.

When operating at a comparatively high temperature, for instance, between to 200" "C an unreacted alkylene oxide such as propylene oxide, makes it presence felt in the increase in pressure or the consistency of a high pressure. However, at a low enough temperature it may happen that the propylene oxide goes in as a liquid. If so, and if it remains unreacted there is, of course, an inherent danger and appropriate steps must be taken to safeguard against this possibility; if need be a sample must be withdrawn and examined for unreacted propylene oxide. One obvious procedure, of course, is to oxypropylate at a modestly higher temperature, for instance, at 140 to 150 C. Unreacted oxide affects determination of the acetyl or hydroxyl value of the hydroxylated compound obtained.

The higher the molecular weight of the compound, i. e., towards the later stages of reaction, the longer the time required to add a given amount of oxide. One possible explanation is that the molecule, being larger, the opportunity for random reaction is decreased. Inversely, the lower molecular weight the faster the reaction takes place. For this reason, sometimes at least, increasing the concentration of the catalyst does not appreciably speed up the reaction, particularly when the product subjected to oxyalkylation has a comparatively high molecular weight. However, as has been pointed out previously, operating at a low pressure and a low temperature even in large scale operations as much as a week or ten days time may elapse to obtain some of the higher molecular weight derivatives from monohydric or dihydric materials.

In a number of operations the counterbalance scale or dial scale holding the propylene oxide bomb was so set that when the predetermined amount of propylene oxide had passed into the reaction the scale movement through a time operating device was set for either one to two hours so that reaction continued for l to 3 hours after the final addition of the last propylene oxide and thereafter the operation was shut down. This particular device is particularly suitable for use on larger equipment than laboratory size autoclaves, to wit, on semi-pilot plant or pilot plant size, as well as on large scale size. This final stirring period is intended to avoid the presence of unreacted oxide.

In this sort of operation, of course, the temperature range was controlled automatically by either use of cooling water, steam, or electrical heat, so as to raise or lower the temperature. The pressuring of the propylene oxide into the reaction vessel was also automatic insofar that the feed stream was set for a slow continuous run which was shut ofi in case the pressure passed a predetermined point as previously set out. All the points of design, construction, etc., were conventional including the gauges, check valves and entire equipment. As far as I am aware at least two firms, and possibly three, specialize in autoclave equipment such as I have employed in the laboratory, and are prepared to furnish equipment of this same kind. Similarly pilot plant equipment is available. This point is simply made as a precaution in the direction of safety. Oxyalkylations, particularly involving ethylene oxide, glycide, propylene oxide, etc., should not be conducted except in equipment specifically designed for the purpose.

Example 1a The particular autoclave used was one having a capacity of approximately 1 /2 gallons. The speed of the stirrer could be varied from 150 to 350 R. P. M. 500 grams of sorblde were mixed with 50 grams of caustic soda. The mixture was charged into the autoclave. The reaction pot was flushed out with nitrogen. The autoclave was sealed and the automatic devices set for injecting a total of 2700 grams of propylene oxide in four hours. The pressure regulator was set for a maximum of 35 pounds per square inch. This meant that the bulk of the reaction could take place, and probably did take place, at a lower pressure. This comparatively low pressure was the result of the fact that considerable catalyst was added, in fact the percentage was very high, as indicated. The propylene oxide was added comparatively slowly at a rate of about 700 grams per hour and, more important, the selected temperature range was to C., i. e., slightly above the boiling point of water. The initial introduction of propylene oxide was not started until the heating devices had raised the temperature to approximately the boiling point of water. At the end of the reaction a sample was taken and oxypropylation proceeded as in Example 2a, immediately succeeding.

Example 2a.

2,000 grams of the reaction mass previously identified as Example 1 a, were permitted to remain in the autoclave. No additional catalyst was added. To this there was added 1089 grams of propylene oxide. The time required to add this smaller amount of propylene oxide in the second stage was three hours. In all other respects the operation was the same as in Example la, preceding. The temperature was the same and the pressure was the same. At the end of the reaction period part of the sample was withdrawn and oxypropylation proceeded as in Example 3a, following.

Example 3a In this instance again 2,000 grams of the prior oxypropylation product identified as Example 2a were permitted to remain in the autoclave. No additional catalyst was added. In this instance the operation was substantially the same as in Example 1a., preceding, particularly in regard to temperature and pressure. The amount of oxide added was 1149 grams. This was added in a 4-hour period. At the end of the reaction period part of the sample was withdrawn and the residue subjected to further oxypropylation as outlined in Example 4a, immediately succeeding.

Example 4a Example 50.

In this instance 1800 grams of the reaction mass identified as Example 4a., preceding, were permitted to remain in the autoclave. No additional catalyst was added. 1035 grams of propylene oxide were added during this fifth stage. The

9. conditions of. oxypropylation were substantially thesame; as in. Example 10., preceding, particularly inregard to pressure and temperature. The time required to add the propylene oxide in its 10. particularly .dicarboxy: acids; such as adipic acid, phthalic. acid, or anh ide. succinic; acid, d.i=- glycollic acid, sebacic. acid, azelaic acid... aconitic acid, maleic or anhydride,v .citraconic. acid or final stage was six hours. anhydride, maleic acid; or anhydrideadducts, as

What has been said herein is presented in tabuobtained by the. Diels-A'lder. reaction from: prolarv form in Table 1 immediately following, with ductssuchas maleic anhydride, and cyclopenta some added information as to molecular weight diene. Such acids shouldbe heat stable so they and as to solubility of the reaction product in are not decomposed during esterification. They water, xylene and kerosene. may contain as many as- 36 carbon atoms as,

TABLE 1 Composition Before Composition at End M W .Max. by Max. Pres, 1%: 11. 0. Oxide Cata- Theo. H. 0. Oxide cm- 533,; 3?" g;-

Amt., Amt, lyst, M01. Amt, Amt, lyst, min Sq 1.1L

grs. grs grs. Wt. grs. grs. grs.

1a 500 50 936 500 2,700 50 875 110-115 35 4' 2a.. 308 1,661 31 1, 447 308 2,750 31 1,355 110-115 35 3 3a.. 199 1,781 2, 295 199 2,930 20 2,015 110-115 3 4. 41L. 120 1,768 12 3,826 120 3,030 12 3, 234 110-115 35 5% 5a.- 68.51, 724.65 6.85 6,225 68.5 2,860 6.88 4,168 110-115 5 7 6a. 4111,7531 4.2 8,445 12.1 2, 395 4.2 5,035 110-115 35 s 1 The hydroxylated compound is sorbide.

All the examplesv were insoluble in water, and for example, the acids obtained by: dimerization soluble in xylene, and all but Example 111, were of unsaturated fatty a ids, unsaturated mon soluble in kerosene. oarboXy f y acids, or unsaturated monocare The. final product, i. e., at the end of the boxy acids having 18 carbon atoms. Reference oxypropylation step, was a somewhat viscous to the acid in the hereto appended claims 010.- very pale straw-colored fluid which was waterviously includes the anhyd-rides or any other insoluble. This is characteristic of all various obvious equivalents. My preference, however, is end products obtained in this series. These to use polycarboxy acids haying not over 8 products were, of course, slightly alkaline due carbon atoms. to the residual caustic soda employed. This The production of esters including acidester would also be the case if sodium methylate were (fractional esters) from polyoarboxy acid and used as a catalyst. glycols or other hydroxylated compounds is well Speaking of insolubility in water or solubility known. Needless, to say, various compounds may in kerosene such solubility test can be made be used such as the low molal ester, the ansimply by shaking small amounts of the materials yd de, e 1.0571 Chloride, H e or in a. test tube with water, for instance, using purpose of economy it is customary to use. either 1% to 5% approximately based on the amount he acid or the. anhydrid A onv n i nal proof water present. cedure is employed. On, a laboratory scale one Needless to say, there is no complete convercan employ a resin pot. of the kind described sion of propylene oxide into the desired hy- 5 in U. .S. PatentNo. 2,499,370, dated March 7, 1950 droxylated compounds. This is indicated. by they to DeGroote and Keiser, and particularly. with fact that the theoretical molecular weight based. one or more openingv to permit the use of a on a statistical average greater than the molecuporous spreader. if hydrochloric acid gas is. to lar weight calculated by usual methods on be. used as a catalyst. Such device. or absorpbasis of acetyl or hydroxyl value. Actually, there tion S r n s of minute d' is no completely satisfactory method for dethimbles which are. connected tov a glass tube. termining molecular weights of these types of One can add a u o o ac d uc s Dara-toluene compounds with a high degree of accuracy when sulfonic acid as a catalyst. There is some ohthe molecular weights exceed 2,000. In some jection to this because in some instances there instances the acetyl value or hydroxyl value is some evidence that this acid catalyst tends serves as satisfactorily as an index to the moleo d compose or rearrange the oxypropylated cular weight as any other procedure, subject compounds, and particularly likely to do so if to the above limitations, and especially in the the esterification temperature is too high. In higher molecular weight range. If any difiiculty the case of polycarboxy acids such as diglycollic i-s'encountered in the manufacture of the esters acid, which is strongly acidic there is no need as described in Part 2 the stoichiometrical to add any catalyst. The use of hydrochloric amount of acid or aci co p Should be gas has one advantage over the paratoluene. taken which corresponds to the indicated acetyl sulfonic acid and that is that at the end of or hydroxyl value. This matter has been dis.- th ti t can be removed by flushing out cussed in the literature and is a matter of common knowledge and requires no further elaboration. In fact, it is illustrated by some of the examples appearing in the patent previously mentioned.

PART 2 As previously pointed out the present invention is concerned with acidic esters obtained from the oxypropylated derivatives described in Part 1, immediately preceding, and polycarboxy acids,

with nitrogen, whereas there is no reasonably- 11 catalyst whatsoever and to insure complete dryness of the diol as described in the final procedure just preceding Table 2.

The products obtained in Part 1 preceding may contain a basic catalyst. As a general procedure I have added an amount of half-concentrated hydrochloric acid considerably in excess of what is required to neutralize the residual catalyst. The mixture is shaken thoroughly and allowed to stand overnight. It is then filtered and refluxed with the xylene present until the water can be separated in a phase-separating trap. As soon as the product is substantially free from Water the distillation stops. This preliminary step can be carried out in the flask to be used for esterification. If there is any further deposition of sodium chloride during the reflux stage needless to say a second filtration may be required. In any event the neutral or slightly acidic solution of the oxypropylated derivatives described in Part 1 is then diluted further with sufiicient xylene decalin, petroleum solvent, or the like, so that one has obtained approximately a 45% solution. To this solution there is added a polycarboxylated reactant as previously described, such as phthalic anhydride, succinic acid or anhydride, diglycollic acid, etc. The mixture is refluxed until esterification is complete as indicated by elimination of water or drop in carboxyl value. Needless to say, if one produces a half-ester from an anhydride such as phthalic anhydride, no water is eliminated. However, if it is obtained from diglycollic acid, for example, water is eliminated. All such procedures are conventional and have been so thoroughly described in the literature that further consideration will be limited to a few examples and a comprehensive table.

Other procedures for eliminating the basic residual catalyst, if any, can be employed. For example, the oxyalkylation can be conducted in absence of a solvent or the solvent removed after oxypropylation. Such oxypropylation end product can then be acidified with just enough concentrated hydrochloric acid to just neutralize the residual basic catalyst. To this product one can then add a small amount of anhydrous sodium sulfate (sufficient in quantity to take up any water that is present) and then subject the mass to centrifugal force so as to eliminate the sodium sulfate and probably the sodium chloride formed. The clear somewhat viscous straw-colored amber liquid so obtained may contain a small amount of sodium sulfate or sodium chloride but, in any event, is perfectly acceptable for esterification in the manner described.

It is to be pointed out that the products here described are not polyesters in the sense that there is a plurality of both diol radicals and acid radicals; the product is characterized by having only one diol radical.

In some instances and, in fact, in many instances I have found that in spite of the dehydration methods employed above that a mere trace of water still comes through and that this mere trace of water certainly interferes with the "acetyl or hydro-xyl value determination, at least when a number of conventional procedures are used and may retard esterification, particularly where there is no sulfonic acid or hydrochloric acid present as a catalyst. Therefore, I have preferred to use the following procedure: I have employed about 200 grams of the diol as described in part 1, preceding; I have added about 60 grams of benzene, and then refluxed this mixture in the glass resin pot using a phase-separating trap until the benzene carried out all the water present as water of solution or the equivalent. Ordinarily this refluxing temperature is apt to be in the neighborhood of 130 to possibly 150 C. When all this water or moisture has been removed I also withdraw approximately 20 grams or a little less benzene and then add the required amount of the carboxy reactant and also about 150 grams of a high boiling aromatic petroleum solvent. These solvents are sold by various oil refineries and, as far as solvent effect act as if they were almost completely aromatic in character. Typical distillation data in the particular type I have employed and found very satisfactory is the following:

I. B. P., 142 C. 50 ml. 242 C.

5 ml., 200 C. 55 ml. 244 C. 10 ml., 209 C. 60 ml. 243 C. 15 ml., 215 C. 65 m1. 252 C. 20 mL, 216 C. 70 ml. 252 C. 25 m1. 220 C. 75 ml. 260 C. 30 m1. 225 C. ml. 264 C. 35 ml. 230 C. m1. 270 C. 40 ml. 234 C. m1. 280 C. 45 ml. 237 C. ml. 307 C.

After this material is added, refluxing is continued and, of course, is at a high temperature, to wit, about to C. If the carboxy reactant is an anhydride needless to say no water of reaction appears; if the carboxy reactant is an acid water of reaction should appear and should be eliminated at the above reaction temperature. If it is not eliminated I simply separate out another 10 Or 20 cc. of benezne by means of the phase-separating trap and thus raise the temperature to or C., or even to 200 C., if need be. My preference is not to go above 200 C.

The use of such solvent is extremely satisfactory provided one does not attempt to remove the solvent subsequently except by vacuum distillation and provided there is no objection to a little residue. Actually, when these materials are used for a purpose such as demulsification the solvent might just as well be allowed to remain. If the solvent is to be removed by distillation, and particularly vacuum distillation, then the high boiling aromatic petroleum solvent might well be replaced by some more expensive solvent, such as decalin or an alkylated decalin which has a rather definite or close range boiling point. The removal of the solvent, of course, is purely a conventional procedure and requires no elaboration.

In the appended table Solvent #7-3, which appears in numerous instances, is a mixture of 7 volumes of the aromatic petroleum solvent previously described and 3 volumes of benzene. This was used, or a similar mixture, in the manner previously described. A large number of the examples indicated were repeated employing decali n, using this mixture and particularly with the preliminary step of removing all the water. If one does not intend to remove the solvent my preference is to use the petroleum solvent-benzene mixture although obviously any of the other mixtures, such as decalin and xylene, can be employed.

The data included in the subsequent tables, 1. e., Tables 2 and 3, are self-explanatory, and very complete and it is believed no further elaboration is necessary:

TABLE 2 M01. Ex. P Theo. 23 Actual Wt. l 9 No. of M. W. Hy- Based Acid Hyor droxyl dmx I on Hyd Polycarboxy Reactant caiboxy Ester H 0 M vent; Actual Cmpd Cmpd. H. O. H. V. (grs.) ant 2a 1, 447 77. l 82. 8 l, 356 226 Phthalic Anhydride 49 2a 1, 447 77. 1 82. 8 l, 356 226 Maleic Anhydride 33- 211 1,447 77.1 82.8 1,356 226 CitraconieAnhydricl 37' 2a 1, 447 77. l 82. 8 1, 356 226 Suecinic Anhydride 33 2a 1,447 77.1 82.8 1, 353 225 DiglycollicAmd'... 45 311 2,295 48.8 55-7 2,.015 202. Phthalic AnhYdride; 30 3a 2, 295 48.8 55.7 2,015 202 Maleic Anhydride 20 3a 2, 296 48.8 55. 7 2, 015 202 Citraconic Anhydride 22 3a 2, 296 48.8 55.7 2,015 202 Succinic Anhydride 20 3a, 2,296 48.8 55.7 2,015 202 Diglycollic Acid 27 411 3,826 29.35 38.8 3,234 215 Phthalic Anhydridem" 20 411 3,826 29.36 34. 8 3, 234 216 'Maleic Anhydride 13.5 441 3,826 29.35 34.8. 3,234 216 Citraconic Anhydride... 15. 4a 3, 826 29. 35 34.8 3, 234 216 Succinie Anhydride 13; 411. 3,826 29.35 34.3 3,234 216' D1glyc0llicAcid 18. 5a 0,225 18. 05 25. 95 4,168 209 Phthalic Anhydride. 15 5a 6, 225' 18:05 23. 95 4,103 200 Maleic Anhydride 10 5a 6, 225 18. 05 26. 95 4, 168 209 Citracomc Anhydride 11 5a 6, 225 18. O5 26. 95 4, 168 209 Succinic Anhydride. 10 5a 3,225 18.05 26. 95 4,103 209 Diglycollic Acid 1.3;5 612 8,445 13.32 22.35 5,035 202 Phthalic Anhydride- 12. 6a 8, 445 13. 32 22. 35 5, 035 202 Maleic Anhydride 8 6a 3, 445 13. 32 22. 35 5, 035 202 Oitraconic'Anhydriden 9 6a 8, 445 13. 32 22. 35 5, 035 202 Succinic Anhydride. 9 611 8,445 13. 32 22. 35 5,035 202 DiglyccllicAcid 9 TABLE? 3 cation does not produce a clear product a check should be made to see if an inorganic salt such as Amt Esterifiw Time of Water S0d11lm chloride or sodium sulfate is not precipi- Soh'ent g g g g g gf 85g 30 tailing out. Such salt should be eliminated, at f least for exploration experimentation, and can be 7 3 225 148 23/ N removed by filtering. Everything else being equal 1 one. 254 173 3% None; as the mm of the molecule increases and the re- ;j: 3 active hydroxyl radical represents a smaller'frac- 7-3 302 183 4y tion of the entire molecule and thus more difll- 7-3 256 172 3 one. 3 H 223 163 None culty 1s mvolved in obtaining complete esterlfica- 7-3 241 181 4 None. o :2 ff Even under the most carefully controlled con- H 282 152 5% None, W dltlons of oxypropylation involving comparatively g3 low temperatures and long time of reaction there 242 151 3 None are iformed certain compounds whose composition :3 2% $116. is st1ll obscure. Such side reaction products can 270 1 3 3% None. contribute a substantial proportion of the final kg w cogeneric reaction mixture. Various suggestions 7-3 232 168 5% About 1 have been made as'to the nature of these com- CO. 272 152 1% None pounds. such as being cycllc polymers of propyl- 1 311 5 3 4 None, ene oxide, dehydration products Wlth the appear- ;:g $33;- ance of a vinyl radical, or isomers of propylene 7-3 251 155 s Lessthan oxide or der1vatives thereof, 1. e., of an aldehyde, ketone, or allyl alcohol. In some instances an attempt to react the stoichiometric amount of a polycarboxy acid with the oxypropylated derivative results in an excess of the carboxylated reactant for the reason that apparently under conditions of reaction less reactive hydroxyl radicals are present then indicated by the hydroxyl value. Under such circumstances there is simply a residue of the carboxylic reactant which can be removed by filtration or, if desired, the esterification procedure can be repeated using an appropriately reduced ratio of carboxylic reactant.

Even the determination of the hydroxyl value by conventional procedure leaves much to be desired due either to the cogeneric materials previously referred to, or for that matter, the presence of any inorganic salts or propylene oxide. Obviously this oxide should be eliminated.

As has been pointed out previously an alkaline catalyst is generally employed in the oxypropylation of the hexide. I have found it convenient. to remove the excess of catalyst using hydrochloric acid in the manner previously noted. If a trace of hydrochloric acid remains in the oxypropylated hexide esterification seems to proceed with considerable ease. This is particularly true in the case of the anhydrides and also in the case of diglycollic acid.

The procedure for manufacturing the esters has been illustrated by preceding examples. If for any reason reaction does, not take place in a manner that is acceptable, attention should be directed to the following details: (a). Recheck the hydroxyl or acetyl value of the oxypropylated product and use a stoichiometrically equivalent amount of acid; (b) if the reaction does not proseed with reasonable speed either raise the temperatures indicated or else extend the period of time up to 12 or 16 hours if need be; (c) if necessary, use of paratoluene sulfonic acid or some other acid as a catalyst; (d) if the esterifi- The solvent employed, if any, can be removed from the finished ester by distillation and particularly vacuum distillation. The final products or liquids are generally very pale straw color to amber in color, and show moderate viscosity. They can be bleached with bleaching clays, filtering chars, and the like. However, for the. pure 15 pose of demulsification or the like color is not a factor and decolorization is not justified.

In the above instances I have permitted the solvents to remain present in the final reaction mass. In other instances I have followed the same procedure using decalin or a mixture of decalin and benzene in the same manner and ultimately removed all the solvents by vacuum distillation. Appearances of the final products are much the same as the diols before esterification and in some instances were somewhat darker in color and had a reddish cast and perhaps somewhat more viscous.

PART 3 Previous reference has been made to the fact that diols such as polypropyleneglycol of approximately 2,000 molecular weight, for example, have been esterified with dicarboxy acids and employed as demulsifying agents. On first examination the difference between the herein described products and such comporable products appears to be rather insignificant. In fact, the difierence is such that it fails to explain the fact that compounds of the kind herein described may be, and frequently are, or better on a quantitative basis than the simpler compound previously described, and demulsify faster and give cleaner oil in many instances. The method of making such comparative tests has been described in a booklet entitled Treating Oil Field Emulsions, used in the Vocational Training Courses, Petroleum Industry Series, of the American Petroleum Institute.

The difference, of course, does not reside in the carboxy acid but in the diol. Momentarily an effort will be made to emphasize certain things in regard to the structure of a polypropylene glycol, such as polypropylene glycol of a 2000 molecular weight. Propylene glycol has a primary alco hol radical and a secondary alcohol radical. In this sense the building unit which forms polypropylene glycols is not symmetrical. Obviously, then, polypropylene glycols can be obtained, at least theoretically, in which two secondary alcohol groups are united or a secondary alcohol group is united to a primary alcohol group, etherization being involved, of course, in each instance.

Usually no effort is made to differentiate between oxypropylation taking place, for example, at the primary alcohol unit radical of the secondary alcohol radical. Actually, when such products are obtained, such as a high molal polypropylene glycol or the products obtained in the manner herein described one does not obtain a single derivative such as HO-(RO) nH in which n has one and only one value, for instance, 14, 15 or 16, or the like. Rather, one obtains a cogeneric mixture of closely related or touching homologues. These materials invariably have high molecular weights and cannot be separated from one another by any known procedure without decomposition. The properties of such mixture represent the contribution of the various individual members of the mixture. On a statistical basis, of course, it can be appropriately specified. For practical purposes one need only consider the oxypropylation of a monohydric alcohol because in essence this is substantially the mechanism involved. Even in such instances where one is concerned with a monohydric reactant one cannot draw a single formula and say that by following such procedure one can readily obtain 80% or 90% or 100% of such compound. However, in the case of at least monohydric initial reactants one can readily draw the formulas of a larg number of compounds which appear in some of the probable mixtures or can be prepared as components and mixtures which are manufactured conventionally.

Simply 'by way of illustration reference is made to the co-pending application of DeGroote, Wirtel and Pettingill, Serial No. 109.791, filed August 11, 1949 (now Patent 2,549,434, granted April 17, 1951) However, momentarily referring again to a monohydric initial reactant it is obvious that if one selects any such simple hydroxylated compound and subjects such compound to oxyalkylation, such as oxyethylation, or oxypropylation, it becomes obvious that one is really producing a polymer of the alkylene oxides except for the terminal group. This is particularly true where the amount of oxide added is comparatively large, for instance, 10, 20, 30, 40, or 50 units. If such compound is subjected to oxyethylation so as to introduce 30 units of ethylene oxide, it is well known that one does not obtain a single constituent which, for the sake of convenience, may be indicated as RO C2H4O) 30H. Instead, one Ohtains a cogeneric mixture of closely related homologues, in which the formula may be shown as the following, RO(C2H4O)nI-I, wherein 'n, as far as the statistical average goes, is 30, but the individual members present in significant amount may vary from instances where n has a value of 25, and perhaps less, to a point where 11, may represent 35 or more. Such mixture is, as stated, a cogeneric closely related series of touching homologous compounds. Consider-able investigation has been made in regard to the distribution curves for linear polymers. Attention is directed to the article entitled Fundamental Principles of Condensation Polymerization, by Flory, which appeared in Chemical Reviews, volume 39, No. 1, page 137.

Unfortunately, as has been pointed out by Flory and other investigators, there is no satisfactory method, based on either experimental or mathematical examination, of indicating the exact proportion of the various members of touching homologous series which appear in cogeneric condensation products of the kind described. This means that from the practical standpoint, i. e., the ability to describe how to make the product under consideration and how to repeat such production time after time without difficulty, it is necessary to resort to some other method of description, or else consider the value of n, in formulas such as those which have appeared previously and which appear in the claims, as representing both individual constituents in which n has a single definite value, and also with the understanding that n represents the average statistical value based on the assumption of completeness of reaction. This may be illustrated as follows: Assume that in any particular example the molal ratio of the propylene oxide to the diol is 30 to 1. Actually, one obtains products in which n probably varies from 10 to 20, perhaps even further. The average value, however, is 15, assuming, as previously stated, that the reaction is complete. The prodnot described by the formula is best described also in terms of method of manufacture.

However, in the instant situation it becomes obvious that if ordinary high molal polypropylene glycol is compared to a string of white beads of various lengths the diols herein employed as intermediates are characterized by the presence n and n are usually not equal. For instance, if one introduces 15 moles of propylene oxide, 11. and n could not be equal insofar that-the nearest approach to equality is where the value of n is 7 and ,n is 8. However, even in the case .of an even number such as 20, 30, 40 or 5.0., it is also obvious that n and n will not be equal in light of what has been said previously. Both sides of the molecule are not going to grow with equal rapidity, i. e., to the same size. Thus the diol herein employed is differentiated from polypropylene diol 2000, for example, in that (a) it carries a hetero unit, 1. e., a unit other than a propylene glycol or propylene oxide unit, (1)) such unit is off center, and (c) the eflect of that unit, of .course, must have some eifect in the range with which the linear molecules can be drawn together by hydrogen binding or van der Waals forces, or whatever else may be involved.

What has been said previously can be emphaslzed in the following manner. It has been pointed out previously that in the last formula immediately preceding, 11. or n could be zero. Under the conditions of manufacture as described in Part 1 it is extremely unlikely that n is ever zero. However, such compounds can be prepared readily with comparatively little difiiculty by resorting toa blocking effect or reaction. For instance, if the oxyprop-ylated dihydroxylated hexide is esterified with a low molal acid such as acetic acid mole for mole and such product subjected to oxyalkylation using a catalyst, such as sodium methylate and guarding against the presence of any water, it becomes evident that all the propylene oxide introduced, for instance 15 to 80 molecule per polyhydric alcohol necessarily must enter at one side only. If such product is then saponified so as to decompose the acetic acid ester and then acidified so as to liberate the water-soluble acetic acid and the water-insoluble diol a separation can be made and such diol then subjected to esterification as described in Part 2, preceding. Such esters, of course, actually represent products where either 12 or n is zero. Also intermediate procedures can be employed, 1. e., following the same esterification step after partial oxypropylation. For instance, one might oxypropylate with onehalf the ultimate amount of propylene oxide to be used and then stop the reaction. One could then convert this partial oxypropylated intermediate into an ester by reaction of one mole of acetic acid with one mole of a diol. This ester could then be oxypropylated with all the remaining propylene oxide. The final product so obtained could be saponified and acidified so as to eliminate the water-soluble acetic acid and freethe obviousl unsymmetrical diol which, incidentally, should also be kerosene-soluble.

From a practical standpoint I have found no advantage in going to this extrastep but it does emphasize the difierence in structure between the herein described diols employed as intermediates and high molal polypropylene glycol, such as polypropylene glycol 2000.

PART 4 Conventional demulsifying agents employed in the treatment of oil field emulsions are used as such, or after dilution with any suitable solvent,

such as water, petroleum hydrocarbons, such as benzene, toluene, xylene, tar acid oil, cresol,v

anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such as methyl alcohol, ethyl :al-

cohol, denatured alcohol, propyl alcohol, .butyl alcohol, hexyl alcohol, octyl alcohol, etc., may be Miscellaneous solvents employed as diluents. such as pine oil, carbon tetrachloride, sulfur dioxide extract obtained in the refining of petroleum, etc., may be employed as diluents. Similarly, the material or materials employed as the de-' mulsifying agent of my process may be admixed with one or more of thesolvents customarily used in connection with conventional demulsifying agents. Moreover, said material or materials may be used alone or in admixture with other suitable well-known classes of demulsifying agents.

It is well known that conventional demulsifying agents may be used in a water-soluble form, or in an oil-soluble form, or both oil-and water-solubility. Sometimes they may be used in a form which exhibits relatively limited oil-solubility. However, since such reagents are frequently used in a ratio of 1 to 10,000

or 1 to 20,000, or 1 to 30,000, or even 1 to 40,000, or 1 to 50,000 as in desalting practice, such an apparent insolubilit in oil and water is not significant because said reagents undoubtedly have solubility within such concentrations. This same fact is true in regard to the material ormaterials employed as the demulsifying agent of my process.

In practicing my process for resolving petroleum emulsions of the water-in-oil type, a treating agent or demulsifying agent of the kind above described is brought into contact with or caused to act upon the emulsion to be treated, in any of the various apparatus now generally used to resolve or break petroleum emulsions with a chemical reagent, the above procedure being used alone or in combination with other demulsifying procedure, such as the electrical dehydration process.

One type of procedure is to accumulate a volume of emulsified oil in a tank and conduct .a batch treatment type of demulsification procedure to recover clean oil. In this procedure the emulsion is admixed with the demulsifier, for example by agitating the tank of emulsion and slowly dripping demulsifier into the emulsion. In some cases mixing is achieved by heating the emulsion while dripping in the demulsifier, depending upon the convection current in the emulsion to produce satisfactory admixture. In a third modification of this type of treatment, a circulating pump withdraws emulsion from, c. g., the bottom of the tank, and reintroduces it into the top of the tank, the demulsifier being the suction side of said well-head or at some point between the well head and the final oil storage tank, by means of" in a form exhibiting an adjustable proportioning mechanism or proportioning pump. Ordinarily the flow of fluids through the subsequent lines and fittings sufices to produce the desired degree of mixing of demulsifier and emulsion, although in some in stances additional mixing devices may be introduced into the flow system. In this general procedure, the system may include various mechanical devices for withdrawing free water, separating entrained water, or accomplishing quiescent settling of the chemicalized emulsion. Heating devices may likewise be incorporated in any of the treating procedures described herein.

A third type of application (down-the-hole) of demulsifier to emulsion is to introduce the demulsifier either periodically or continuously in diluted or undiluted form into the well and to allow it to come to the surface with the well fluids, and then to flow the chemicalized emulsion through any desirable surface equipment, such as employed in the other treating procedures. This particular type of application is decidedly useful when the demulsifier is used in connection with acidification of calcareous oil-bearing strata, especially if suspended in or dissolved in the acid employed for acidification.

In all cases, it will be apparent from the foregoing description, the broad process consists simply in introducing a relatively small proportion of demulsifier into a relatively large proportion of emulsion, admixing the chemical and emulsion either through natural flow or through special apparatus, with Or without the application of heat, and allowing the mixture to stand quiescent until the undesirable water content of the emulsion separates and settles from the mass.

The following is a typical installation.

A reservoir to hold the demulsifier of the kind described (diluted or undiluted) is placed at the well-head where the effluent liquids leave the well. This reservoir or container, which may vary from gallons to 50 gallons for convenience, is connected to a proportioning pump which injects the demulsifier drop-wise into the fluids leaving the well. Such chemicalized fluids pass through the fiowline into a settling tank. The settling tank consists of a tank of any convenient size, for instance, one which will hold amounts of fluid produced in 4 to 24 hours (500 barrels to 2000 barrels capacity), and in which there is a perpendicular conduit from the top of the tank to almost the very bottom so as to permit the incoming fluids to pass from the top of the settling tank to the bottom, so that such incoming fluids do not disturb Stratification which takes place during the course of demulsiflcation. The settling tank has two outlets, one being below the water level to drain off the water resulting from demulsiflcation 0r accompanying the emulsion as free water, the other being an oil outlet at the top to permit the passage of dehydrated oil to a second tank, being a storage tank, which holds pipeline or dehydrated oil. If desired, the conduit or pipe which serves to carry the fluids from the well to the settling tank may include a section of pipe with battles to serve as a mixer, to insure thorough distribution of the demulsifier throughout the fluids, or a heater for raising the temperature of the fluids to some convenient temperature, for instance, 120 to 160 F., or both heater and mixer.

Demulsification procedure is started by simply setting the pump so as to feed a comparatively large ratio of demulsifier, for instance, 115,000. As soon as a complete break or satisfactory demulsiflcation is obtained, the pump is regulated until experience shows that the amount of demulsifier being added is just sufiicient to produce clean or dehydrated oil. The amount being fed at such stage is usually 1 10,000, 1 15,000, 1 20,000, or the like.

In many instances the oxyalkylated products herein specified as demulsifiers can be conveniently used without dilution. However, as previously noted, they may be diluted as desired with any suitable solvent. For instance, by mixing '75 parts by weight of the product of Example 10b with 15 parts by weight of xylene and 10 parts by weight of isopropyl alcohol, an excellent demulsifier is obtained. Selection of the solvent will vary, depending upon the solubility characteristics of the oxyalkylated product, and of course will be dictated in part by economic considerations, i. e, cost.

As noted above, the products herein described may be used not only in diluted form, but also may be used admixed with some other chemical demulsifier. A mixture which illustrates such combination is the following:

Oxyalkylated derivative, for example, the product of Example 10b, 20%;

A cyclohexylamine salt of a polypropylated naphthalene monosulfonic acid, 24%;

An ammonium salt of a polypropylated naphthalene mono-sulfonic acid, 24%;

A sodium salt of oil-soluble mahogany petroleum sulfonic acid, 12%;

A high-boiling aromatic petroleum solvent,

Isopropyl alcohol, 5%.

The above proportions are all weight percents.

PART 5 Previous reference has been made to oxyalkylating agents other than propylene oxide, such as ethylene oxide. Obviously variants can be prepared which do not depart from what is said herein but do produce modifications. The diol, i. e., the dihydroxylated initial compound, to wit, the hexide, can be reacted with ethylene oxide in modest amounts and then subjected to oxypropylation provided that the resultant derivative is (a) water-insoluble, (b) kerosene-soluble, and (c) has present 15 to alkylene oxide radicals. Needless to say, in order to have water-insolubility and kerosene-solubility the large majority must be propylene oxide. Other variants suggest themselves as, for example, replacing propylene oxide by butylene oxide.

More specifically then one mole of sorbide can be treated with 2, 4 or 6 moles of ethylene oxide and then treated with propylene oxide so as to produce a water-insoluble, kerosene-soluble diol in which there are present 15 to 80 oxide radicals as previously specified. Similarly the propylene oxide can be added first and then the ethyene oxide, or random oxyalkylation can be employed using a mixture of the two oxides. The compounds so obtained are readily esterified in the same manner as described in part 2, preceding. Incidentally, the diols described in part 1 or the modifications described therein can be treated with various reactants such as glycide, epichlorohydrin, dimethyl sulfate, sulfuric acid, maleic anhydride, ethylene imine, etc. If treated with epichlorohydrin or monochloracetic acid the resultant product can be further reacted with a tertiary amine such as pyridine, or the like, to give quaternary ammonium compounds. If treated with maleic anhydride to give a total ester the resultant can be treated with sodium bisulfite to yield a sulfosuccinate. Sulfo groups can be introduced also by means of a sulfating agent as previously suggested, or by treating the chloroacetic acid resultant with sodium sulfite.

I have found that if such hydroxylated compound or compounds are reacted further so as to produce entirely new derivatives, such new derivatives have the properties of the original hydroxylated compound insofar that they are effective and valuable demulsifying agents for resolution of Water-in-oil emulsions as found in the petroleum industry, as break inducers in doctor treatment of sour crude, etc.

Having thus described my invention what I claim as new and desire to obtain by Letters Patent, is:

1. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula Hoo0)..-R "1 oc3Ha),.0R'o oammn mooomw in which R is a hexide radical; n and n are numerals with the proviso that n and 12 equal a sum varying from 15 to 80, and n is a whole number not over 2 and R is the radical of the polybasic acid COOH in which n" has its previous significance, and with the further proviso that the parent dihydroxylated compound prior to esterification be water-insoluble.

2. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula in which R. is a sorbide riadcal; n and n are numerals with the proviso that n and n equal a sum varying from 15 to 80, and n" is a whole number not over 2, and R is the radical of the polybasic acid coon in which n" has its previous significance, and with the further proviso that the parent dihydroxylated compound prior to esterification be water-insoluble.

3. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula in which R is a sorbide radical; n and n are numerals with the proviso that n and 11. equal a sum varying from 15 to 80, and n" is a whole 22 number not over 2, and R is the radical of the polybasic acid.

in which n" has its previous significance, and with the further proviso that the parent dihydroxylated compound prior to esterification be water-insoluble and kerosene-soluble.

4. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula:

in which R is a sorbide radical; n and n are numerals with the proviso that n and 11/ equal a sum varying from 15 to 80, and n" is a whole number not over 2, and R is the radical of the polybasic acid COOH in which n has its previous significance, said polycarboxy acid having not over 8 carbon atoms; and with the further proviso that the parent dihydroxylated compound prior to esterification be water-insoluble and kerosene-soluble.

5. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula in which R is a sorbide radical; n and n are numerals with the proviso that n and 12' equal a sum varying from 15 to 80, and R is the radical of the dicarboxy acid /CO0H said dicarboxy acid having not over 8 carbon atoms; and with the further proviso that the parent dihydroxylated compound prior to esterification be water-insoluble and kerosene-soluble.

6. The process of claim 5 wherein the dicarboxy acid is phthalic acid.

7. The process of claim 5 wherein the dicarboxy acid is maleic acid.

8. The process of claim 5 wherein the dicarboxy acid is succinic acid.

9. The process of claim 5 wherein the dicarboxy acid is citraconic acid.

10. The process of claim 5 wherein the dicarboxy acid is diglycollic acid.

MELVIN DE GROOTE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,552,528 De Groote May 15, 1951 2,562,878 Blair Aug. 7, 1951 

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPE CHARACTERIZED BY SUBJECTING THE EMULSION TO THE ACTION OF A DEMULSIFIER INCLUDING HYDROPHILE SYNTHETIC PRODUCTS; SAID HYDROPHILE SYNTHETIC PRODUCTS BEING CHARACTERIZED BY THE FOLLOWING FORMULA 